The genetic code and its characteristics

Genetic code

• It is a total genetic message encoded within the base sequence of the axons of the coding region of a gene.
• It is the collection of codons that specify amino acids.

The genetic code and its characteristics

Codon

• Every individual three-letter code word of genetic code is called a codon.
• It consists of three consecutive bases, composed of A, T, G, and C at different combinations.
• Each codon represents an amino acid.
• There are altogether 64 codons

      1. Sense codon= 61

      2. None sense codon: 3

• These are used to terminate protein synthesis.
• They are:- UAG, UAA, UGA

The genetic code and its characteristics

Characteristics of genetic code

1. Universality

• A codon representing a definite amino acid is universal and applicable to all organism
• The same codon specifies the same amino acid in all species.

2.  Degeneracy/ Redundancy

• For a given amino acid there is more than one codon( except for methionine and tryptophan which have only one codon)
• Sense codon= 61
• Total amino acid= 20

So, for one amino acid, there is more than one codon

3. Specificity/ unambiguous

•  Forgiven codon there is only one amino acid.

4. Nonoverlapping

• Consecutive triplet codons do not share any base and follow the strict sequence along with the reading frame of mRNA.

The genetic code and its characteristics

5. Commaless/ Nonpunctuated

• Between the consecutive codons, there are no extra bases to separate the codons.

Example:- ABC def ghi

Also read: Biochemistry Questions & Answers